Receptor

Receptor is a protein molecule that receives chemical signals from outside a cell. When such chemical signals bind to a receptor, they cause some form of cellular/tissue response, including a change in the electrical activity of a cell. There is a range of different types of receptors, including Ion channel-linked receptors, G protein-linked receptors, and Enzyme-linked receptors.

Types of Receptors

Ion channel-linked receptors

Ion channel-linked receptors, also known as ligand-gated ion channels, are a group of transmembrane ion-channel proteins which open to allow ions such as Na+, K+, Ca2+, and/or Cl− to pass through the membrane in response to the binding of a chemical messenger (i.e., a ligand), such as a neurotransmitter.

G protein-linked receptors

G protein-linked receptors, also known as seven-(pass)-transmembrane domain receptors, 7TM receptors, heptahelical receptors, serpentine receptor, and G protein-coupled receptors (GPCRs), constitute a large protein family of receptors that sense molecules outside the cell and activate inside signal transduction pathways and, ultimately, cellular responses.

Enzyme-linked receptors

Enzyme-linked receptors, also known as catalytic receptors are a group of proteins that are composed of an extracellular domain, which is capable of binding with a specific ligand, and an intracellular domain, which can function as an enzyme or can have enzymatic activity, such as protein kinase activity or guanylate cyclase activity.

Function

Receptors are found in all living organisms, from viruses to vertebrates. They are used in the transmission of signals in the nervous system, in the immune response, in cell growth and death, and in many other physiological functions.

See also

• Cell signaling
• Signal transduction
• Neurotransmitter
• Hormone